The slush molding method has been used widely for applications typified by automobile interior materials, adhesives for interlining, etc. because of its advantages such as being capable of easily molding products with complicated shapes (undercut, deep drawing, etc.), being capable of making uniform the thickness of products, and being capable of affording high yield rate of materials.
While a soft polyvinyl chloride powder has mainly been used as a slush molding material, polyurethane resins have also been used in recent years (see, for example, Patent Document 1).
However, a skin for an instrument panel, which is an automobile interior material, is demanded to be reduced in its thickness from a cost reduction point of view, and in reducing thickness, it is necessary to satisfy higher resin strength as compared with ordinary skin strength. However, a skin being high in resin strength is low in elasticity development rate of resin during cooling after thermoforming and, therefore, at the time of removal of the skin from a mold or real-stitching aiming at high design quality, there arises a problem that the skin is deformed and wrinkles are formed. Moreover, a resin material being low in resin strength cannot be formed into a thin film because tear or the like of a skin occurs and the heat resistance of the material deteriorates during the formation of a thin film.